Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UC San Diego Physicists Reveal Secrets of Newest Form of Carbon

12.06.2008
Using one of the world’s most powerful sources of man-made radiation, physicists from UC San Diego, Columbia University and Lawrence Berkeley National Laboratory have uncovered new secrets about the properties of graphene—a form of pure carbon that may one day replace the silicon in computers, televisions, mobile phones and other common electronic devices.

Graphene—a single layer of carbon atoms arranged in a honeycombed lattice—has a number of advantages over silicon. Because it is an optically transparent conductor of electricity, graphene could be used to replace current liquid crystal displays that employ thin metal-oxide films based on indium, a rare metal that is becoming increasingly expensive and likely to be in short supply within a decade. The problem for scientists is that not much is known about its optical and electronic properties because graphene, which was discovered only four years ago, has resisted traditional forms of spectroscopy.

In this week’s advance online publication of the journal Nature-Physics, the physicists report that they used the Advanced Light Source at the Berkeley lab—one of the most powerful and versatile sources of electromagnetic radiation, from the infrared to x-ray region, in the world—to reveal some of those secrets. The researchers said that their study shows that the electrons in graphene strongly interact not only with the honeycomb lattice, but also with each other.

“Infrared and optical experiments are capable of providing some of the most valuable insights into the electronic properties of materials, including interactions between electrons in a material,” said Dimitri Basov, a professor of physics at UC San Diego who headed the project. “But it was extremely difficult to measure the absorption of light in a single monolayer of graphene, because not much light is absorbed. To do this, we had to start with a very bright light. It was spectroscopy to the extreme.”

The radiation from the Advanced Light Source, or ALS, is about 100 million times brighter than that from the most powerful X-ray tube, the source used in a dentist's machine. High brightness means that the radiation is highly concentrated and many photons per second can be directed onto a tiny area of a material.

Just as dentists use x rays to see inside your gums, scientists use the ALS’s radiation—generated by accelerating electrons around a circular racetrack at close to the speed of light—to look inside materials.

“It took some difficult experimental work to make this measurement,” said Basov. “It was by far the most complicated measurement we have ever done.”

Zhiqiang Li, a UCSD physics graduate student in Basov’s group, was the first author of the paper. Other principal investigators involved in the discovery were Michael Martin, staff scientist at the Berkeley laboratory’s ALS; Philip Kim, an associate professor of physics at Columbia University; and Horst Stormer, a professor of physics at Columbia and winner of the 1998 Nobel Prize in Physics.

Funding for the project was provided by the U.S. Department of Energy.

Kim McDonald | EurekAlert!
Further information:
http://www.ucsd.edu

More articles from Physics and Astronomy:

nachricht Spintronics: Researchers show how to make non-magnetic materials magnetic
06.08.2020 | Martin-Luther-Universität Halle-Wittenberg

nachricht Manifestation of quantum distance in flat band materials
05.08.2020 | Institute for Basic Science

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: ScanCut project completed: laser cutting enables more intricate plug connector designs

Scientists at the Fraunhofer Institute for Laser Technology ILT have come up with a striking new addition to contact stamping technologies in the ERDF research project ScanCut. In collaboration with industry partners from North Rhine-Westphalia, the Aachen-based team of researchers developed a hybrid manufacturing process for the laser cutting of thin-walled metal strips. This new process makes it possible to fabricate even the tiniest details of contact parts in an eco-friendly, high-precision and efficient manner.

Plug connectors are tiny and, at first glance, unremarkable – yet modern vehicles would be unable to function without them. Several thousand plug connectors...

Im Focus: New Strategy Against Osteoporosis

An international research team has found a new approach that may be able to reduce bone loss in osteoporosis and maintain bone health.

Osteoporosis is the most common age-related bone disease which affects hundreds of millions of individuals worldwide. It is estimated that one in three women...

Im Focus: AI & single-cell genomics

New software predicts cell fate

Traditional single-cell sequencing methods help to reveal insights about cellular differences and functions - but they do this with static snapshots only...

Im Focus: TU Graz Researchers synthesize nanoparticles tailored for special applications

“Core-shell” clusters pave the way for new efficient nanomaterials that make catalysts, magnetic and laser sensors or measuring devices for detecting electromagnetic radiation more efficient.

Whether in innovative high-tech materials, more powerful computer chips, pharmaceuticals or in the field of renewable energies, nanoparticles – smallest...

Im Focus: Tailored light inspired by nature

An international research team with Prof. Cornelia Denz from the Institute of Applied Physics at the University of Münster develop for the first time light fields using caustics that do not change during propagation. With the new method, the physicists cleverly exploit light structures that can be seen in rainbows or when light is transmitted through drinking glasses.

Modern applications as high resolution microsopy or micro- or nanoscale material processing require customized laser beams that do not change during...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“Conference on Laser Polishing – LaP 2020”: The final touches for surfaces

23.07.2020 | Event News

Conference radar for cybersecurity

21.07.2020 | Event News

Contact Tracing Apps against COVID-19: German National Academy Leopoldina hosts international virtual panel discussion

07.07.2020 | Event News

 
Latest News

Anode material for safe batteries with a long cycle life

06.08.2020 | Power and Electrical Engineering

Turning carbon dioxide into liquid fuel

06.08.2020 | Life Sciences

Tellurium makes the difference

06.08.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>